Meissner



Jan. 9, 1934. MEI SNER 1,943,031

PROCESS OF CONTINUOUS PRODUCTION OF NITROPENTAERYTHRITE, TETRANITROMETHYLANILINE TRINITRORESORCINE AND SIMILAR NITROCOMPOUNDS Filed Aug. 25, 1930 Patented Jan. 9, 1934 PROCESS OF CONTINUOUS PRODUCTION OF NETROPENTAERYTHRITE, TETRANITRO- METHYLANILINE, TRINITRORESORCINE, AND SIMILAR NITROCOMPOUNDS Josef Meissner, Burbach, Germany Application August 25, 1930, Serial No. 477,790, and in Germany September 28, 1929 1 ill-aim.

Heretofore tetranitromethylaniline, nitropentaerythrite and trinitroresorcine have been produced in charges in a number of operations. The operations mainly dealt with the preparation of the sulphonic acid, the nitration, washing and recrystallization, whereby the process of nitration constitutes the principal process, which takes up a great length of time and calls for the greatest care, because generally it is extremely 19 difficult to keep up the temperature during the process. Further the poisonous nitric oxide fumes of which a large quantity escapes during the nitration are a permanent danger for the operators' The length of time necessay for the production of tetranitromethylaniline, nitropentaerythrite and trinitroresorcine solely depends on the process of nitration and in the case of tetranitromethylaniline takes up from 5 to 6 hours, in the event of nitropentaerythrite from 3 to 4 /2 hours and in the case of trinitroresorcine from 5 to 6 hours.

As a further example of showing the produced quantity it is mentioned, that for producing approximately 200 kilograms in 8 hours from 10 to 12 nitrating apparatus are necessary, each of which can master one nitration. This large number of nitrating apparatus and the necessary recipient vessels and acid conduits call for a considerable outlay of money for erecting the apparatus and buildings. A large number of workmen is necessary for attending to the very extensive plant.

To sum up, the drawbacks of the known process of interrupted nitration are:--

1. Long time needed by the process of nitration in the several nitrating apparatus and therefore small efllciency of a large plant.

2. Escape of poisonous fumes, so that the attendance is rendered dangerous.

3. High costs of erecting the nitration building and high costs of the apparatus.

4. High costs necessary for repairs, particularly caused by long acid conduits.

- 5. High costs of service.

6. Loss during the production owing to repairs and blazing up of the charges.

It is the aim to carry out every chemical process in an uninterrupted operation in order to 50 avoid the drawbacks of interrupted operation. and it has been found. that also the nitration of tetranitromethylaniline, nitropentaerythrite, trinitroresorcine and like members of the nitro group can be carried out in an uninterrupted manner.

Further during the production of nitropentaerythrite it has been found, that pentaerythrite is soluble in sulphuric acid, so that a sulphonic acid can be producedjust in the same way as is the case during the production of tetra- 0 nitromethylaniline and trinitroresorcine.

For carrying out the uninterrupted nitration of tetranitromethylaniline, nitropentaerythrite and trinitroresorcine, the nitric acid and the sulfuric, acid or the raw materials are uninterg5 ruptedly supplied into the apparatus, and the recovered acid together with the nitrated product are discharged therefrom. The temperature is controlled in suitable manner. The nitric oxide fumes, developed during the nitration, are exhausted and subsequently condensed.

A construction of the apparatus for uninterruptedly carrying out the nitration of tetranitromethylaniline, nitropentaerythrite and trinitroresorcine is illustrated in the drawing.

The primary products are charged into the apparatus by way of supply-pipes 1 and 2. A system of agitators 4 is arranged in the casing 3 .of the apparatus and mounted in a bearing 5. The apparatus is provided with a jacket 6 and a lid '7. 89 The product of nitration and the recovered acids leave the apparatus by way of a pipe 8. The nitrous fumes, developed in the apparatus, are exhausted by way of the pipe 9.

The advantages of the uninterrupted nitration 35 are:-

1. Short length of time necessary for the. proies of nitration.

2. No escape of poisonous fumes from the apparatus, because the closure is absolutely tight. g 3. Low costs of the apparatus and building and greater efficiency.

4. Low costs of service.

5. Practically no repairs.

6. No accidents owing to repairs and blazing 95 up of the charges.

7. Considerable reduction of the. costs of production.

The following example shows the superiority of uninterrupted nitration compared with the inter- 1( rupted nitration.

An apparatus for interrupted operation of a diameter of about 200 millimetres and of a height of 1 to 2 metres yields in 8 hours about 200 to 250 kilograms. For attaining the same efficiency 1. in an uninterrupted process, 10 nitrating apparatus each of a volume for 300 litres would be necessary. It is quite obvious that a large number of apparatus, buildings and workmen are necessary therefor. 1

I claim:

A process for the continuous production of nitro-pentaerythrite which comprises dissolving pentaerythrite in sulfuric acid, adding nitric acid, passing the resulting solution over an extended ascending path while agitating and maintaining 

